Husk and dice your tomatillos. Place tomatillos, onion, garlic and chile pepper into saucepan. Season with cilantro, oregano, cumin, and salt. Add water. Bring to a boil over high heat, then reduce heat to medium-low, and simmer until the tomatillos are soft, 10-15 minutes.

If you prefer a thicker consistency, drain water. Using a blender or food processor, carefully puree the ingredients in water in batches until smooth.